Welding is a process that joins components together and may be used in the manufacture or repair of an article. For example, in the oil and gas industry, welding may be used to join steel pipes to one another. By way of another example, linear friction welding may be used to join a disk and a plurality of aerofoils to form a bladed disk (commonly referred to as a Blisk).
Welding may cause residual stress in the article due to: heat flowing from the weld area that causes the joint to expand; thermal expansion and contraction that leaves permanent stress; tensile residual stress that exists in the weld metal and the adjacent base metal; and compressive residual stress that exists away from the weld metal. The residual stress may result in cracks arising in the article without any external loads being applied when the article is in a hostile environment (for example, a high temperature environment).